Troughing idler assembly having lim ited troughing movement for low clearance operations



R. F. LO PRES Tl TROUGHING IDLER AS April 30, 1963 3,087,601

SEMBLY HAVING LIMITED TROUGHING MOVEMENT, FOR LOW CLEARANCE OPERATIONS 2Sheets-Sheet 1 Filed Dec. 30, 1959 .....U r mm M D: m0 4 .L f M w/ mApril 30, 1963 R. F. LO PRESTI 3,087,601

vTROUGHING IDLER ASSEMBLY HAVING LIMITED TROUGHING MOVEMENT FOR LOWCLEARANCE OPERATIONS Filed Dec. 30, 1959 2 Sheets-Sheet 2 Fig. 4 Roy Ffi i sti BY Par/KW far/er fl/zameys United States Patent Ofi ice3,087,601 TROUGHING IDLER ASSEMBLY HAVING LIM ITED TROUGHING MOVEMENTFOR LOW CLEARANCE OPERATIONS Roy F. Lo Presti, Chicago, 111., assignorto Goodman bgalrlllufacturing Company, Chicago, 111., a corporation moisFiled Dec. 30, 1959, Ser. No. 862,815 8 Claims. (Cl. 198-192) Thisinvention relates generally to flexible rope side frame conveyors, andparticularly to a troughing idler assembly for low rope operations whichretains substantially all the vertical flexibility of the conventionalfully flexible sausage roller assembly utilized in high clearance andabove ground operations.

Rope side firame conveyors of the type illustrated in the Craggs et al.Patent No. 2,773,257 have come into increasingly widespread use inrecent years due to their many inherent desirable characteristics. Amongthese are low cost, high carrying capacity, ease of installation andmaintenance, and easy adaptability to all conveyor environments.

This type of conveyor generally comprises a pair of rope side framessuch as wire ropes which are supported in generally parallelrelationship at predetermined intervals along a conveying course such asa mine run by a plurality of support structures. The support structuresmay take the form or ground engaging support stands or hanger structuresconnected to an overhead support such as the mine roof. A plurality oftroughing idler assemblies are hung from the rope side frames atintervals to form a bed which supports the conveying reach of an endlessflexible conveyor belt. Return roller assemblies are located atintervals along the conveying course to support the return reach of thebelt. These return roller assemblies may be suspended directly from therope side frames or carried by other suitable supporting structures suchas the rope side frame support stands. In general, since the returnroller assemblies carry no load other than the weight of the returnreach of the belt, they are positioned at substantiallygreater'intervals along the conveying course than are the conveyingtroughing idler assemblies.

I he basic structure illustrated in the aforementioned Craggs et al.patent may be infiinitely varied to satisfy the demands of varyingconveyor environments. For example, the fully flexible troughing rollerassembly is well suited to operations in which head room is no problem,such as large vein coal mining and above ground operatoins. In lowclearance operations, such as narrow seam coal mining, the fullyflexible roller assembly may occasionally run into difliculty,especially if the rope tension is low. Under such conditions theconveying reach may drop tar enough to interfere with the return reachor the conveyor belt which invariably runs directly beneath theconveying reach.

In addition, it is sometimes diflicult in low clearance operations tobuild in to the fully flexible idler assembly the structure needed toproperly reorient at least the wing rollers of the assembly to properlytrain the belt as it moves thereacross. Also, because of the crampedspace condition, lubrication of the roller bearings may sometimes beinconvenient, particularly when the rollers are connected directly inline with one another.

Accordingly, a primary object of this invention is to provide atroughing idler assenrbly for low rope operation which retains all thedesirable belt troughing characteristics of a fully flexible troughingroller assembly through at least a limited range of flexure of therollers with respect to one another.

Another object is to provide a troughing idler assembly 3,087,601Patented Apr. 30, 1963 2 for low rope operation which provides fullflexibility of the individual rollers by displacing the rope side framesoutwardly and even relatively slightly upwardly under load to therebycounteract the cumulative sag eifect of the strands under loadconditions.

Another object is to provide a troughing idler assembly for low ropeoperations in which belt training is efiected by an automaticreorientation of the wing rollers in response to reversal of belttravel.

Yet a further object is to provide a troughing idler assembly for lowrope operations which substantially eliminates the lifting of the outerends of the wing rollers as they are swung from one training position toanother.

Yet a further object is to provide a low rope troughing idler assemblywhich provides easy access to the individual roller bearings forlubrication and inspection.

Yet a further object is to provide a low rope troughing idler assemblyas fully flexible as above ground sausage idler assemblies to apredetermined point beyond which further liexure of the individualrollers with respect to one another is prevented by a graduallystiffening fiexure limiting means which limits the troughing contour andprevents interference of the center roller with the return reach.

A further object of the invention is to provide a low rope troughingidler assembly fully as flexible as above ground troughing idlerassemblies to a predetermined point beyond which further flexure of therollers with respect to one another is prevented by positive limit meanswhich take effect at or immediately before the limit of the graduallystiflening flexure limiting means is reached.

Other objects and advantages of the invention will become apparent upona reading of the following descrip tion.

The invention is illustrated more or less diagrammatically in theaccompanying drawings, wherein:

FIGURE 1 is a cross sectional view through a rope side firame conveyorillustrating the invention in elevation;

FIGURE 2 is a top plan view with the belt omitted for clarity, takensubstantially along the line 2. 2 or FIG- URE 1;

FIGURE 3 is a partial left side view taken substantially along the line3-3 of FIGURE 1; and

FIGURE 4 is a partial view of the roller assembly illustrating therelative positions assumed by the roller sup porting structure in loadedand unloaded conditions.

Like reference numerals will be used to refer to like parts throughoutthe following description of the drawings.

The conveyor illustrated in cross section in FIGURE 1 consistsessentially of a pair of flexible rope side frames 10 and 11 which aresupported by a pair of telescoping vertically adjustable support stands12 and 13 resting on the mine floor F. The rope side frames are receivedin a pair of U-shaped saddle members 14 and 15 welded or otherwisesuitably secured to the top of the telescoping support stands. A rigidcross bar 16 welded to the telescoping support stands maintains the topof the stands, and consequently the gauge of the flexible rope sideframes, a fixed distance apart. Since the details of the rope side framesupporting structure and the means for vertically maintaining the seatsformed in the U-shaped saddle members in a common horizontal plane donot of themselves form an integral part of the invention, they are notfurther illustrated or described. The roof, which may for example be theroof of a coal mine, is indicated at R. From the relative closeness ofthe roof to the floor, it can be seen that the conveyor is installed ina low clearance environment.

A return roller 17, shown in this instance as secured to the telescopingsupport stands 12 and 13, supports the return reach 18 of a flexibleconveyor belt. Since the details of the connection of the return rollerto the support stands is not essential to an understanding of theinvention, it is not further illustrated or described.

The unique conveying troughing idler assembly of the present inventionis indicated generally at 20. The assembly includes essentially anintermediate or center primary load carrying roller 21 flanked by a pairof end or wing rollers 22, 23. The rollers form in effect a bed whichsupports the conveying reach 24 of a flexible conveyor belt. The rollersare serially disposed with respect to one another across the width ofthe conveyor, but, as is apparent from FIGURE 2, the center roller 21 isoffset from the wing rollers 22, 23 along the longitudinal axis of theconveyor.

Means for supporting the rollers in a freely flexible relationship areindicated generally at 30. The roller supporting means comprises ineffect a flexible frame consisting of a pair of side strut members 31,32 which are pivotally connected at their inner ends to a centerconnecting brace member 33. The outer ends of the side strut members 31,32 are welded or otherwise suitably secured as at 34 to means 35, 36 forconnecting the roller supporting means and rollers to the flexible ropeside frames. In this instance, the connecting means are illustrated asrope clamps, one part of which is welded to the side strut members, butit will be understood that any suitable connecting means may beutilized.

The side strut members and center connecting brace are illustrated inthis instance as consisting of flat plates whose length is substantiallylonger than their width, and the width substantially greater than thethickness. As best illustrated in FIGURE 2, the strut members andconnecting brace are joined for flexing movement with respect to oneanother by pivot pins 38, 39 passing through aligned collars 40 which inturn are welded to the ends of the brace and side struts. The wingrollers are supported on the side struts by structure which will now bedescribed in detail. Since the mode of connection of each roller to itsassociated side strut is essentially the same, only right wing roller 23will be described.

An upwardly extending roller supporting arm 42 is welded to the innerend of side strut 32, as best illustrated in FIGURE 4. The upper end ofthe arm is slotted to receive the right wing roller shaft 23a, and thearm may be slightly curved to provide adequate clearance between it andthe lower inner edge of the roller. A second roller supporting armstructure extends upwardly from the right or outer end of side strut 32,as viewed in FIGURE 1. The outer supporting arm structure may beintegrally formed with side strut 32, as best illustrated in FIGURE 4.The outer roller supporting arm includes a generally vertically upwardlyextending lower portion 43 and an upper slightly inwardly directedportion 44. An elongated pivot arm 45 whose upper end is apertured toreceive the outer end of wing roller shaft 23a is pivotally connected tothe upper portion 44 of the outer arm by pivot pin 46. The pivotalconnection 46 permits swinging movement of the outer end of the wingroller in a direction generally parallel to the longitudinal axis of theconveyor, for a purpose which will be explained hereinafter. A tubularreinforcing member 47 is welded to the lower end of inner arm 42 and theupper end of upper portion 44 to provide additional rigidity to thestructure. Cotter pins, not numbered, maintain pivot pin 46 in place andprevent unintended axial movement of pivot arm 45 along the outer end ofroller shaft 23a. In FIGURE 3, which shows the supporting structure forleft wing roller 22 but which is identical to that of right wing roller23, a triangular reinforcing plate 48 has been welded along its shortleg to the connecting means 35 and along its long leg to the lowerportion 43 of the outer roller supporting arm. The illustrated supportstructure provides an effective flexure point between rollers at thepivot pin connections 38 and 39.

The center roller 21, which may be of somewhat greater length than thewing rollers 22, 23, is supported on a center connecting brace 33 by apair of upstanding brackets 50, 51 which are slotted as at 52 to receivethe ends of center roller shaft 21a. With the exception of the outerends of the wing rollers, the connection of the roller shafts to itsassociated supporting structure rs affected by milling parallel flatsonto the shaft ends and then slipping the shafts into the slots in thearms, the slots being narrower than the diameter of the shafts. A closetolerance between the milled flats and supporting arm slots is notdesired. In the case of the wing roller shafts, a certain amount oflooseness or play in the joint is necessary in order to permit the outerends of the wing rollers to swing back and forth in a direction roughlyparallel to the longitudinal axis of the conveyor. relatively loosetolerance is also desirable to permit the rollers to be easily installedand removed.

In the illustrated embodiment, the rollers are free to flex with respectto one another in a generally vertical plane, and as can be seen fromFIGURE 1, there is a considerable overlap between the ends of the centerroller and the inner ends of the wing rollers. This feature providesgood belt contact with therollers in both loaded and unloadedconditions, even if the belt is relatively stiff.

Means for reorienting the wing rollers into a belt training position inresponse to reversal of belt travel is illustrated best in FIGURES 2 and3. When the conveying reach 24 travels in the directoin of arrow 60,wing roller 22 will take the position illustrated in FIG- URE 3. A pairof opposed outwardly projecting flanges 6'1, 62, which in effect aremerely the upturned edges of upper portion 44, act as stop means whichdefine the path of traverse of the elongated pivot arm 45 about pivotpoint 46. In the position shown, flange 62 positions roller 22 a fewdegrees downstream, as can be best seen in FIGURE 2. When the directionof belt travel is reversed, as indicated by the phantom arrow 63, leftflange 61 limits the position of pivot arm 45 to a position indicateddiagrammatictlly by the radial arm 64 which similarly positions theroller 22 a few degrees in the opposite direction. Representative rangesof movement are on the order of 2 to 5 degrees.

Pivot arm 45 is so proportioned that the outer end of wing roller 22will traverse a substantially straight path in its movement from onetraining position to the other. There will, of course, be a very smallrise and fall of the wing roller shaft but the length of pivot arm 45 issuch as to enable the repositioning force exhibited by belt 24 on theroller to easily swing the roller from one position to another.

Positive limiting means for limiting the amount of flexure between thewing and center rollers are illustrated best in FIGURES 2 and 4. A pairof blocks or checks 65, 66 are welded along their lower edges as at 67to the upstream side of center reinforcing brace 33, as best shown inFIGURE 4. Each chock includes an abutment surface 68 which is alignedwith the upper portion of arm 42 supporting the inner end of wing rollershafts 22a and 23a. When the wing rollers assume their point of maximumdeflection with respect to center roller 21, arm 42 will impinge againstabutment surface 68. The angle of abutment surface 68 is so designedthat when the point of maximum deflection has been reached, the flexurepoints 38 and 39 will be at a vertically higher level than the points ofconnection of the side strut members 32, 33 to the flexible strands 10and 11.

The use and operation of the invention are as follows:

In FIGURE 1, the low rope troughing idler assembly of the presentinvention is shown in an unloaded condition. In this position, theflexure points 38, 39 between the wing and center rollers lie atconsiderable distance above the flexible strands 10 and 11 and theconnecting means 35, 36. It will be understood that in someinstallations it may be convenient to extend the side strut members 31,32 slightly outwardly beyond the flexible rope side frames. In thisconstruction, the assembly should be so proportioned that the flexn-repoints 38, 39 should be maintained above the points of connection of theroller supporting frame 30 to the ropes.

When a load is imposed on the assembly, the wing rollers 22, 23 flex tothe position illustrated in FIGURE 4. In this position, the inner endsof the wing rollers substantially overlap the ends of the center roller21. Similarly the flexu-re points 38, 39 drop vertically downwardly fromtheir original position, indicated at X in FIGURE 4, to the illustratedposition. At the same time the flexible strands 1'0 and 11 move fromtheir original position, indicated at Y in FIGURE 4, to the illustratedposition. Side strut member 32, of course, moves from the position,indicated at Z in FIGURE 4, to the illustrated position. In effect, theflexible roller supporting structure has been extended due to aflattening out resulting from the imposed load. Since the flexure pointshave not moved inwardly and the side strut members 32, 33 aresubstantially bodily rigid, the ends of the side struts actually n'serather than fall as the rollers drop downwardly. This rise in elevationof the outer ends of the side strut members counteracts the sag effectof the flexible strands and thus the net downward displacement of thestrands may be rather slight, especially in operations in which thestrands are rather tight.

The amount of flexure between the rollers is limited in the firstinstance by the deflection limit of the flexible rope side frames. As asafety feature, the stop blocks 65, 66 are provided to insure that theside struts 32, 31 will not swing upwardly above center reinforcingbrace 33. The abutment surface 68 on the stop blocks should be sodesigned however that arms 42 impinge against it only slightly beforethe deflection limit of the rope side frames is reached to therebyutilize the full upward movement of the ropes due to extension of theroller supporting means.

Although a preferred embodiment of the invention has been illustratedand described, it will be understood that further modifications willsuggest themselves to those skilled in the art upon a reading of theforegoing specification. Accordingly, the foregoing description shouldbe taken as merely illustrative and not definitive, and the scope of theinvention should be limited only by the following appended claims.

I claim:

1. A troughing idler assembly for a belt conveyor of the type in whichan endless belt is supported by a plurality of troughing idlerassemblies which are carried by a pair of rope side frames supported inparallel, coplanar relationship to one another along a conveying course,said troughing idler assembly including, in combination,

a conveyor belt supporting roller assembly, said roller assemblyincluding at least an intermediate roller flanked by at least a pair ofwing rollers,

extensible and retractible frame means supporting the rollers in fullyflexible relationship to one another throughout at least a limited rangeof flexing movement, said frame means being extensible in response toimposition of load on the roller assembly and retractible in response toa decrease in load on the roller assembly, and

means for connecting the frame means and the roller assembly supportedthereby to the rope side frames of a rope side frame belt conveyor.

2. The troughing idler assembly of claim 1 further characterized by andincluding means for repositioning at least the outermost Wing rollersinto a belt training position automatically in response to reversal ofthe direction of belt travel.

3. The troughing idler assembly of claim 2 further characterized in thatthe wing roller repositioning means includes elongated pivot arms, thelower end portions of which are pivotally connected to the frame meansand the upper end portions to the end portions of the outermost wingrollers, the inner end portions of the outermost wing rollers beingnon-rigidly connected to the frame means to thereby enable the wingrollers to flop to and fro along a path generally parallel to thedirection of belt travel into a belt training position in response topassage of the belt thereover, said pivot arms being of a lengthsufficiently long to eliminate substantially all upward component ofmovement of the outer end portions of the rollers as the rollers movefrom one training position to another.

4. The troughing idler assembly of claim 3 further characterized by andincluding a pair of stop members carried by the roller supporting meanslying in the path of movement of the pivot arms to thereby define atraverse of said pivot arms and consequently the belt training positionsof the wing rollers.

5. A troughing idler assembly for a belt conveyor of the type in whichan endless belt is supported by a plurality of troughing idlerassemblies which are carried by a pair of rope sideframes supported inparallel, coplanar relationship to one another along a conveying course,said troughing idler assembly including, in combination,

a conveying belt supporting roller assembly, said roller assemblyincluding at least an intermediate roller flanked by at least a pair ofwing rollers,

an extensible and retractable frame supporting the rollers in fullyflexible relationship to one another throughout at least a limited rangeof flex-ing movement, said frame having a generally central portion inraised position flanked by end portions, said central portion adapted toflex with the end portions to permit the frame to be laterally extendedin response to imposition of a load on the assembly and frame, saidframe retracted in response to a decrease in load on the assembly sothat the raised portion is lowered during extension and raised duringretraction,

and means for connecting the frame and the roller assembly supportedthereby to the rope sideframes of a rope sideframe belt conveyor.

6. A troughing idler assembly for a belt conveyor, said troughing idlerassembly including, in combination,

a plurality of generally serially disposed belt supporting rollersincluding at least an intermediate roller flanked by at least a pair ofwing rollers,

and bodily extensible and retractible means for supporting the rollersin freely flexible relationship with respect to one another throughoutat least a limited range of flexing movement, said bodily extensible andretractible roller supporting means including a Pair of substantiallyrigid side strut members, each of whose inner end portions are pivotallyconnected to the flexure point between a wing and intermediate roller,each of said side strut members being connectable at a point remote fromits inner end portion to an associated rope side frame, said points ofconnection lying at a lower level than the flexure points in an unloadedcondition of the assembly to thereby enable the side strut members toswing out.- wardly as the flexure points move downwardly under load.

7. The troughing idler assembly of claim 6 in which the length of theside strut members is so proportioned hat t e deflection l mit of therope side frames will be reached before the points of connection of theside strut members to the rope side frames rise above the flexurepoints.

8. The troughing idler assembly of claim 7 further characterized :by andincluding limit means operatively engageable with the side strut membersfor positively References Cited in the file of this patent UNITED STATESPATENTS 5 Muller Sept. 11, 1934 8 Kendall Nov. 7, 1939 Wood Mar. 26,1940 Hoeck Mar. 24, 1942 Salmons Apr. 7, 1959 Bergmann June 9, 1959

6. A TROUGHING IDLER ASSEMBLY FOR A BELT CONVEYOR, SAID TROUGHING IDLERASSEMBLY INCLUDING, IN COMBINATION, A PLURALITY OF GENERALLY SERIALLYDISPOSED BELT SUPPORTING ROLLERS INCLUDING AT LEAST AN INTERMEDIATEROLLER FLANKED BY AT LEAST A PAIR OF WING ROLLERS, AND BODILY EXTENSIBLEAND RETRACTIBLE MEANS FOR SUPPORTING THE ROLLERS IN FREELY FLEXIBLERELATIONSHIP WITH RESPECT TO ONE ANOTHER THROUGHOUT AT LEAST A LIMITEDRANGE OF FLEXING MOVEMENT, SAID BODILY EXTENSIBLE AND RETRACTIBLE ROLLERSUPPORTING MEANS INCLUDING A PAIR OF SUBSTANTIALLY RIGID SIDE STRUTMEMBERS, EACH OF WHOSE INNER END PORTIONS ARE PIVOTALLY CONNECTED TO THEFLEXURE POINT BETWEEN A WING AND INTERMEDIATE ROLLER, EACH OF SAID SIDESTRUT MEMBERS BEING CON-